A conventional vehicle control device is configured by various machines including a power conversion device such as a so-called inverter that uses an electric-power semiconductor device and the like, a fin for effectively radiating heat generated from each machine, and the like. Meanwhile, as a recent technical trend, a switching element based on silicon carbide (SiC) that has a high voltage resistance and a low loss and that can operate at a high current, a high temperature, and a high frequency has attracted attention. When a power conversion device is configured by using this switching element, an operation at a high temperature is possible and thus an increase in the temperature of a casing of a vehicle control device (hereinafter, “casing”) tends to be large.
According to a conventional technique represented by Patent Literature 1 mentioned below, there have been employed methods such as that of releasing heat generated from a power conversion device to outside thereof by using a radiation fin, and that of reducing the temperature in a casing by using an air circulating fan and the like arranged in the device.